CDM Smith, 5400 Glenwood Ave., Ste. 300, Raleigh, NC 27612, USA.
Water Res. 2013 Mar 1;47(3):1060-72. doi: 10.1016/j.watres.2012.11.015. Epub 2012 Nov 28.
The purpose of this research was to investigate the performance of treatment with magnetic ion exchange (MIEX) resin followed by ozonation in achieving disinfection goals while controlling bromate and chlorinated disinfection by-product (DBP) formation. Three water samples were collected from raw water supplies impacted by the San Francisco Bay Delta to represent the varying levels of bromide and total organic carbon (TOC) that occur throughout the year. A fourth water was prepared by spiking bromide into a portion of one of the samples. Samples of each water were pre-treated with alum or virgin MIEX resin, and the raw and treated waters were subsequently ozonated under semi-batch conditions to assess the impact of treatment on ozone demand, ozone exposure for disinfection ("CT"), and bromate formation. Finally, aliquots of raw, coagulated, resin-treated, and ozonated waters were chlorinated in order to measure trihalomethane formation potential (THMFP). In the waters studied, MIEX resin removed 41-68% of raw water TOC, compared to 12-44% for alum. MIEX resin also reduced the bromide concentration by 20-50%. The removal of TOC by alum and MIEX resin significantly reduced the ozone demand of all waters studied, resulting in higher dissolved ozone concentrations and CT values for a given amount of ozone transferred into solution. For a given level of disinfection (CT), the amount of bromate produced by ozonation of MIEX-treated waters was similar to or slightly less than that of raw water and significantly less than that of alum-treated water. MIEX resin removed 39-85% of THMFP compared to 16-56% removal by alum. Ozonation reduced THMFP by 35-45% in all cases. This work indicates that in bromide-rich waters in which ozone disinfection is used, MIEX resin is a more appropriate treatment than alum for the removal of organic carbon, as it achieves superior TOC and THM precursor removal and decreases the production of bromate from ozone.
本研究旨在考察磁性离子交换（MIEX）树脂处理后再进行臭氧氧化在实现消毒目标的同时控制溴酸盐和氯化消毒副产物（DBP）形成的效果。从受旧金山湾三角洲影响的原水供应中采集了三个水样，以代表全年溴化物和总有机碳（TOC）的不同水平。第四个水样是通过将溴化物加入其中一个水样的一部分制备的。对每个水样进行预处理，用明矾或 virgin MIEX 树脂处理，然后在半分批条件下对原水和处理水进行臭氧氧化，以评估处理对臭氧需求、臭氧暴露消毒（“CT”）和溴酸盐形成的影响。最后，将原水、混凝水、树脂处理水和臭氧化水的等分试样进行氯化，以测量三卤甲烷形成潜力（THMFP）。在所研究的水中，MIEX 树脂去除了 41-68%的原水 TOC，而明矾则去除了 12-44%。MIEX 树脂还将溴化物浓度降低了 20-50%。明矾和 MIEX 树脂去除 TOC 显著降低了所有研究水样的臭氧需求，导致给定量的臭氧转移到溶液中时溶解臭氧浓度和 CT 值更高。对于给定的消毒水平（CT），MIEX 处理水的臭氧氧化产生的溴酸盐量与原水相似或略低，明显低于明矾处理水。MIEX 树脂去除了 39-85%的 THMFP，而明矾则去除了 16-56%。在所有情况下，臭氧氧化将 THMFP 降低了 35-45%。这项工作表明，在使用臭氧消毒的富溴水中，MIEX 树脂是比明矾更合适的处理方法，因为它可以更好地去除有机碳，从而实现更好的 TOC 和 THM 前体去除，并减少臭氧产生的溴酸盐。
